White space showing up between band groups in proc sgpanel

[Bhando]

I am trying to graph monthly prevalence of 2 diseases over a 6 year time period.  I'm using proc sgpanel to break up the 4 hospitals data.  I'm using the 'band' function to delineate between pre and post an EHR changeover. I created a dummy variable to indicate which EHR was associated with that particular year/month (my x-axis is date). Everything seemed to work...EXCEPT - I have a white band between the banded groups.  I have checked the underlying data several times and there is no gap in the data.  I have read the documentation on the band function, consulted several books and even asked ChatGPT (which did horrible!). 

There's really nothing of value from the log and again, there are no gaps in the data that would indicate there should be a white space here.  

Here is the code (a few var names changed):

proc sgpanel data=enc;
	where fisc_monyr >= '01Nov2015'd;
	panelby hosp / layout=rowlattice onepanel	novarname uniscale=column;
	series x=fisc_monyr y=var1 / Name="var1" legendlabel='varname' lineattrs=(color=black);
	series x=fisc_monyr y=var2 / Name="var2" legendlabel='varname2' lineattrs=(color=crimson);
	band x=fisc_monyr upper=var1 lower=0 /name="band" legendlabel="bandvar" NOMISSINGGROUP
	group=post_gen  transparency=0.7;
	format post_gen post_genf.;
	colaxis grid
			values=('01Nov2015'd, '01Nov2016'd to '01Nov2020'd by year,'01Oct2021'd)
			offsetmin=0 offsetmax=0
			valuesformat=monyy. 
			label="Month-Year"
			;
	rowaxis grid
			label="Encounters per month";
	format fisc_monyr monyy.;
	/*Add refline for ehr date*/
	refline covid_start / name="cov" axis=x label=covid_label 
										labelattrs=(color=black Family=arial
										size=7) legendlabel="COVID19 Start"
										lineattrs=(color=black
										pattern=dot
										thickness=1)
										;
keylegend "var1" "var2" "band";
run;

Here is the band I was referring to: The white space between the blue and red fill.  Is there anything obvious I'm doing wrong here?  Thanks in advance for all your help.  This community has been so great in helping to build this graph. 

[pink_poodle]

Please check out this post:
https://communities.sas.com/t5/Graphics-Programming/Histogram-with-different-fill-colors-beyond-a-sp...

[Bhando]

Thanks so much for this. Will try this this weekend. I'm not sure if this applies to me or not given they're using a histogram. But I trust I'll find some useful info here. THanks again!
Ben

[DanH_sas]

It appears that the gap is created because you start the second band on the next data increment of the series instead of where the first band actually stops. For example, if your X data range went from 1 - 10, and the first band stopped at 5, you are starting the next band at 6 instead of at 5. This leaves a gap between 5 and 6. You probably just need to adjust your data processing to start the second band at the previous "X" step.

Hope this helps!

Dan 

[Bhando]

Wow, Dan, I believe this fixed it!  Thanks so much for this and for sticking with this issue.  I was pretty much ready to give up.